Fatigue crack propagation in thin structures

0354082 - ÚFM 2011 RIV CH eng J - Journal Article
Hutař, Pavel - Seitl, Stanislav - Náhlík, Luboš - Knésl, Zdeněk
Fatigue crack propagation in thin structures.
Key Engineering Materials. Roč. 417-418, - (2010), s. 257-260. ISSN 1013-9826
R&D Projects: GA ČR GA101/08/1623; GA ČR GA106/09/1954; GA ČR GA101/09/0867
Institutional research plan: CEZ:AV0Z20410507
Keywords : fatigue crack * vertex singularity * thin structures
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The influence of specimen thickness on fatigue crack behaviour has been investigated. To this aim the fatigue crack propagation rate has been measured on two different types of test specimens with varying thickness. The change of stress singularity exponent for the crack front due to vicinity of the free surface is considered. To explain the effect of stress singularity changes on obtained experimental results a methodology based on generalized stress intensity factor and strain energy density concept has been used. It is shown that for materials with Poisson’s ratio of about 0.3 the free surface effect does not play a decisive role for specimens with a low level of in-plane constraint but can influence fatigue crack propagation rate in the case of geometries with a high level of the constraint.
Permanent Link: http://hdl.handle.net/11104/0193161